Advanced XMP timings

I've got a gigabyte mobo and I've been trying to get my OC stable for a while now. One of the things I've been trying to nail down are the "Advanced" memory timings: tRRD, tWTR, tWR, tRFC, and CMD.

In the bios there is an option to choose an XMP profile. There is only one profile to select: "profile 1", and when I select it, my timings get set to 9-9-9-24 and the automatic values for "advanced" timings are changed.

I looked all over google trying to find corsair's official specs for these advanced timings, but apparently they don't publish them and they recommend using your motherboard's auto values.

When I look at my spd values in cpu-z, i can only see CAS, tRCD, tRP, tRAS, tRC, and CMD. So, I don't think XMP stores values for the advanced timings.

Basically, what I want to know is this: Is my mobo just guessing at the advanced values based on what it sees in the XMP?

No, your board isn't just guessing at the values of the sub-timings. The DRAM sub-timings, as w/ the four primary timings, are programmed into the SPD of each module by the manufacturer. As long as you have a CPU and board that supports it, you can use CPU-Tweaker to view all of the current sub-timings, and change any of the values from within the GUI.

CPU-Tweaker 1.5
http://www.xtremesystems.org/forums/showthread.php?92190-New-Memory-Tweaker-for-Intel-Chipsets

... or if you have an older setup, you can use MemSet to perform the same function.